diff --git a/index.js b/index.js
index 084a2ffd..564cb2ed 100644
--- a/index.js
+++ b/index.js
@@ -695,12 +695,12 @@ function assign (defaults, configuration) {
   var o = {}
   configuration = configuration || {}
 
+  Object.keys(defaults).forEach(function (k) {
+    o[k] = defaults[k]
+  })
   Object.keys(configuration).forEach(function (k) {
     o[k] = configuration[k]
   })
-  Object.keys(defaults).forEach(function (k) {
-    if (o[k] === undefined) o[k] = defaults[k]
-  })
 
   return o
 }